The present invention relates to a floating caliper-spot-type disc brake, especially for motor vehicles, with one brake support fixed adjacent one side of a brake disc having two arms arranged in the circumferential direction of the brake disc at a given distance from one another and extending over the edge of the brake disc. Brake shoes, which are disposed on both sides of the brake disc, are axially slideably guided in the two arms. A brake caliper embraces the edge of the brake disc and the brake shoes and carries a brake actuation device common to both brake shoes. Pins are detachably fixed at the brake support and extend parallel to the axis of rotation of the brake disc. The brake caliper is axially slideably guided and supported adjacent one end of the pins and a brake shoe connected to the brake caliper is axially slideably guided and supported adjacent the other end of the pins.
In a known brake of this type, such as disclosed in British Pat. No. 1,524,387 published Sept. 13, 1978, the arms of the brake support, by which a brake shoe is directly supported, extend approximately only to the middle of the brake disc and have a longitudinal bore, which serves for the support of the pins.
With one end the pins protrude over the brake disc and in this way form a prolongation of the arms, which support the other brake shoe. The disadvantage of this known disc brake is that it requires a large installation space radially outside the brake disc. Since the pins are stressed by bending by the friction force of the brake shoe supported by them they must have a relatively greater diameter and the brake support arms having the bores which must support the pins must be correspondingly thicker. The thickness of the brake support arms, however, in the end determines the necessary radial installation space outside the brake disc edge. A further disadvantage of the known brake is the different design of the two brake shoes, which results in higher production and stock-keeping costs.
Furthermore, a fixed caliper disc brake is known from German Patent No. DE-AS 1,040,917, published Oct. 9, 1958, in which cylindrical pins are provided for guiding and supporting the brake shoes with the pins being disposed in a guide of the brake housing. These pins rest in grooves in the side walls of the guide, wherein the depth of the grooves is slightly smaller than one half of the pin diameter. The parts of the pins protruding out of the grooves engage recesses in the carrier plates of the brake shoes in such a way that the friction forces occurring during the braking process at the brake shoes are transmitted via the pins to the brake housing. In this known disc brake the arrangement of the pins, however, necessitates separate pins for each brake shoe.
Additionally, a floating caliper-spot-type disc brake is known from German Pat. No. DE-AS 1,625,756, published Oct. 5, 1972 in which two pins fixed at the brake carrier serve the purpose of guiding the brake caliper and holding both brake shoes.
In this known brake the friction forces of the brake shoes are not received by the pins but rather by additional guiding elements of the brake carrier. The guiding elements support one brake shoe via the brake caliper and support the other brake shoe directly. Due to this arrangement the brake has a more complicated construction and its production is more expensive.